钙系磷酸盐化学键合材料的制备及其固化重金属研究

发布时间：2018-04-03 09:34

本文选题：铬铁渣　切入点：磷酸盐化学键合材料　出处：《材料导报》2017年04期

【摘要】：利用富含氧化钙的铬铁渣(FS)和磷酸二氢钾(P)反应制备钙系磷酸盐化学键合材料,并用其作为固化重金属离子(Pb~(2+)、Cd~(2+)、Cu~(2+))基体材料。研究了原料配比、缓凝剂及重金属掺量对胶凝材料初凝时间和抗压强度的影响。结果表明:当P/FS(质量比,下同)为1/4及硼砂掺量为2%时,材料性能最好,自然养护28d和常压蒸汽养护24h抗压强度分别可达25.65 MPa和36.86 MPa。随着重金属掺量的增加,材料抗压强度逐渐降低,掺量为3%时,自然养护28d和蒸汽养护24h试块抗压强度均大于10 MPa,满足建筑材料要求。固化体重金属毒性浸出试验表明:磷酸盐化学键合材料对重金属离子(Pb~(2+)、Cd~(2+)、Cu~(2+))均具有很好的固化效果,浸出浓度远低于相应的鉴别标准。通过XRD、SEM和FTIR分析,钙系磷酸盐化学键合材料固化重金属的机理是通过水化产物的化学键合、吸附以及物理包裹作用将Pb~(2+)、Cd~(2+)、Cu~(2+)固化在材料中。
[Abstract]:Calcium phosphate chemical bonding materials were prepared by the reaction of calcium rich ferrochrome slag (FS) and potassium dihydrogen phosphate (KDP), and used as the base materials for curing heavy metal ions.The effects of raw material ratio, retarder and heavy metal content on the initial setting time and compressive strength of cementitious materials were studied.The results show that when the mass ratio of P / FS is 1 / 4 and the content of borax is 2, the properties of the material are the best. The compressive strength of natural curing 28d and atmospheric steam curing 24h is 25.65 MPa and 36.86 MPa, respectively.With the increase of heavy metal content, the compressive strength of the material decreases gradually. When the content of heavy metal is 3, the compressive strength of the natural curing sample for 28 days and steam curing for 24 hours is more than 10 MPA, which meets the requirements of building materials.The results of toxic leaching test showed that the phosphate chemical bonding material had good solidification effect on heavy metal ions, and the leaching concentration was much lower than the corresponding identification standard.The mechanism of solidification of heavy metals by calcium phosphate chemical bonding materials was determined by XRD and FTIR analysis. The mechanism of solidification of heavy metals was by chemical bonding, adsorption and physical encapsulation of the hydrated products.
【作者单位】：昆明理工大学环境科学与工程学院;西南林业大学理学院;昆明理工大学化学工程学院;
【基金】：NSFC-云南联合基金资助项目(U1137604) 昆明理工大学自然科学研究基金资助项目(kkz320145016) 中国博士后科学基金面上项目(2016M592719)
【分类号】：TQ126.35

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